Reply to Re: Best external backup?

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Posted by Smarty on 05/19/07 13:18

Peter,

The newer DVD dyes may indeed be more stable, and only time will tell
whether they deliver better longevity than the earlier disks. The definition
of "archival" is not at all definitive, so the real issue is whether the
desired "archival" storage period exceeds the time the dye remains stable.
In my case, disks I made 4 years ago, claimed to have a 20 year shelf life,
were unplayable well before the "archival" period I was expecting. Certainly
if Amy only wants to backup her archival materials for 2 years and the dyes
remain stable for 3, then my concern in not applicable to her situation.

My own experience and those of traditional IT managers is that magnetic
tape, rather than optical storage, provides the best combination of economy,
speed, and durability, all things considered. The 40GB Quantum tape drive
for $299 from newegg is a good example of a low cost solution but I would
personally prefer DLT or AIT drives with a SATA interface despite their
higher initial cost.

http://www.newegg.com/Store/SubCategory.aspx?SubCategory=46&name=Tape-Zip-Drives

You are indeed correct that "best" depends on the criteria established, that
each medium has its' pros and cons, and that the informed buyer makes the
"best" decision based on his or her specific needs. For my money, in most
circumstances of data backup (as opposed to video distribution) however, I
would not consider DVD-R the "best".

Smarty


"Peter D" <please@.sk> wrote in message
news:134s72ngdqk9525@corp.supernews.com...
> "Smarty" <nobody@nobody.com> wrote in message
> news:5LCdnUw00bHpdtDbnZ2dnUVZ_tGvnZ2d@adelphia.com...
>> Amy,
>>
>> I respectfully disagree when it comes to using DVD-R as archival storage.
>> I have burned thousands of them beginning around 7 years ago, and ***MANY
>> OF THEM*** are now unreadable. The dyes and soft sectoring are both to
>> blame.
>
> DVD dye and manufacturing technology have advanced significantly in the
> last seven years. As have burners. Quality brand name DVDs (Ritek,
> Verbatin, Fuji, TDK are what I use) are the safest way to go. For burners,
> Pioneer have a very good rep, though I've used LGs for the last 2-3 years
> and have no complaints. As for life cycles, I tend to replace/redo my
> music and video collection (which I store on DVD to prevent the info being
> altered and to reduce the storage on my HDs, and for 'archival' purproses)
> every 2-3 years so I burn new DVDs and file the old ones away 'just in
> case'.
>
>> In particular, the read errors grow as the disks / dyes age, and (unlike
>> some optical formats like DVD-RAM) the drive has trouble accessing
>> sectors, producing check-sum / redundancy code errors from blocks which
>> are unrecoverable.
>
> Thus my suggestion of using accompnaying "PAR" files to error check and
> recreate if necessary. 5-10% pars don't take up much space but can replace
> files as much as 25-30% damages, even more if the damage in each file is
> minor such as might happen with a scratched surface.
>
>> I readily admit that the better brands like Verbatim and Taiyo Yuden are
>> the least affected compared to the cheaper disks, but none are really
>> worthy of being considered "archival" in the long-term sense.
>
> I think it depends on what you mean by "archival" re time length. In my
> case 2-3 years is well within the lifetime of all but the cheapest,
> crappiest DVDs (think Memorex, early Maxell, Kodak, and assorted no-name
> brands) The magnetic fields of Hard Drives fade over time, the mechanical
> components in HDs are prone to failure. MTBF rates are based on ideal
> conditions. Each media has its advantages and disadvantages.
>
>> Also, small error rates are correctible if they are used for their
>> intended video playback purposes, but data storage is less tolerant of
>> bit / block errors when reading, and most burners and software don't even
>> do a "read-after-write" verify step since it is time consuming.
>
> It's always an option -- and a wise one imho. Users, not software, make
> the decision.
>
>> Also, on the subject of time-consuming.....
>>
>> modern 7200 RPM hard disks are cheap, fast, and very reliable, and make
>> backups much, much faster than optical drives, and are vastly more
>> capacious in size. Most video projects and data backups run out of space
>> very quickly when using an optical disk as media, whereas hard disk
>> backup does not have this problem either.
>
> True. But a HD failure can make 500G of data unavailable. A DVD failure
> can make 4.5G of data unavailable. A 500G HD can make 500G almost
> instantly available and 100+ DVDs can be hard to sort through without a
> really good and organised system. Each has an advantage over the other,
> Each has a disadvantage over the other.
>
>> If optical disk storage is your preference, might I suggest you also
>> consider DVD-RAM, a profoundly better format for data archiving.
>
> Agreed. But costly.
>
> The bottom line is that what is "best" depends on the criteria
> established. Each media has pros and cons. The educated user decides based
> on the requirements and needs.
>
>> "Arny Krueger" <arnyk@hotpop.com> wrote in message
>> news:sZWdncG0spGtM9DbnZ2dnUVZ_s2vnZ2d@comcast.com...
>>> "Peter D" <please@.sk> wrote in message
>>> news:134orrdppre2l55@corp.supernews.com
>>>> "Arny Krueger" <arnyk@hotpop.com> wrote
>>>>> <leekazimir@gmail.com> wrote in message
>>>>>> Looking for a good backup solution for big HDV files and
>>>>>> projects.
>>>>>
>>>>>> Currently looking at Maxtor's OneTouch Turbo III
>>>>>> (available in 1 TB or 1.5 TB sizes) and Lacie's BigDisk
>>>>>> 1 TB drives.
>>>
>>>>> I tell my clients that anything by Lacie or one of the
>>>>> prime drive manufacturers (Seagate, Maxtor, Hitachi,
>>>>> Western Digital) is going to be a better choice than
>>>>> some no-name cheapie.
>>>
>>>>> But, watch the GB/$ index. You generally pay a big
>>>>> premium to get the highest possible density. A cursory
>>>>> look suggests that GB/$ is relatively flat up to a
>>>>> surprizing 1 TB.
>>>
>>>>> However, I'd rather have 4 each $100 250 GB external
>>>>> drives rather than 1 each $400 1 TB drive. Shelf space
>>>>> isn't an issue for me at the 3.5 form factor. With the
>>>>> 1 TB drive, one human or hardwaer destorys lots more
>>>>> than it would with 4 smaller drives. If the goal is
>>>>> backup, then the smaller drives give you better options
>>>>> for off site backup. Also, I would probably never buy 4
>>>>> drives at one time, but buy 2 to start for redundcancy
>>>>> and watch the cost per GB of the remainder of my future
>>>>> disk drive farm drop as the price of storage continues
>>>>> to drop.
>>>
>>>> Good advice. I would also recommend DVD-R as a viable
>>>> backup medium. Now before anyone disregards the idea
>>>> because of problems with long-term storage of some DVD
>>>> medium, let me suggest that a combination of recoverable
>>>> methods make it very viable except in the most extreme of
>>>> cases. Simply use a combination of RAR/ZIP or any
>>>> software that can break large files into smaller chunks,
>>>> and create PAR files to act as verifiers and recreators
>>>> should a files get damaged or lost. You can store a lot
>>>> of info on a DVD at very low costs (less than 10c/G), and
>>>> properly stored it is less susceptible to damage than a
>>>> hard drive.
>>>
>>> Good advice. IME well-made, well-stored optical media has all of the
>>> advantages you've mentioned. The biggest problem are the inconvenience
>>> factors.
>
>

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